High-k YCTO thin films for electronics

The high permittivity values reported in rare-earth transition metal oxides ceramics makes them very interesting as alternative gate dielectrics. Here, we summarize our recent results on the yttrium copper titanate (YCTO) thin films under different deposition conditions. Their dielectric properties were studied both in metal-oxide-metal (MIM) and in metal-oxide-semiconductor (MOS) junctions for respectively investigating the material response without parasitic substrate contributions and evaluating the YCTO performance as gate oxide. A strongly dependence of the permittivity from deposition conditions was observed, with a variation from 100 down to 24 at 100 kHz. Such behavior was ascribed to film microstructure variations. Notably, at certain deposition conditions, YCTO thin films possess a higher dielectric permittivity than their bulk counterpart (40.3) in addition to good performances in term of losses. These results demonstrate the applicability of YCTO as alternative high-k gate oxides.